Big Idea 13: Forces and Changes in Motion

Front

What is gravity?

Back

Gravity is a force that pulls objects toward each other, such as the Earth pulling us down.

Front

In which direction does gravity push?

Back

Gravity pushes down.

Front

What is friction?

Back

Friction is a force that opposes motion between two surfaces that are in contact.

Front

If you slide a book down the hallway, what makes the book stop moving?

Back

Friction makes the book stop moving.

Front

What is a balanced force?

Back

Balanced forces are equal in size and opposite in direction, resulting in no change in motion.

Front

What happens when forces are unbalanced?

Back

Unbalanced forces cause an object to start moving, stop moving, or change direction.

Front

What is the unit of force?

Back

The unit of force is Newton (N).

Front

What is the effect of gravity on objects?

Back

Gravity pulls objects toward the center of the Earth, causing them to fall.

Front

What is the relationship between mass and gravity?

Back

The more mass an object has, the stronger the gravitational pull it exerts.

Front

What is motion?

Back

Motion is the change in position of an object over time.